int floorMask; // 自动寻路层
void Awake()
{
    floorMask = LayerMask.NameToLayer("Floor");
}

void Turning()
{
    Ray camRay = Camera.main.ScreenPointToRay(Input.mousePosition);
    RaycastHit floorHit;
    if (Physics.Raycast(camRay, out floorHit, floorMask))
    {
        Vector3 playerToMouse = floorHit.point - transform.position;
        playerToMouse.y = 0;
        Quaternion newRotation = Quaternion.LookRotation(playerToMouse);
        playerRigidbody.MoveRotation(newRotation);
    }
}